Selectivity in the Photoproduct Ratios from Norrish II Reactions of a Homologous Series of 2-Alkanones in Their Melt and Solid Phases. Comparison with Other Environments

1993 ◽  
Vol 58 (1) ◽  
pp. 142-152 ◽  
Author(s):  
Richard G. Weiss ◽  
Sosale Chandrasekhar ◽  
Patricia M. Vilalta
Keyword(s):  
Solid Solutions ◽  
Homologous Series ◽  
Size And Shape ◽  
Solid Phases ◽  
Solvent Molecules

The product ratios from Norrish II reactions of 2-tridecanone, 2-tetradecanone, 2-pentadecanone, 2-hexadecanone, 2-heptadecanone, and 2-nonadecanone have been measured at low percents of conversion in the melt and solid phases. Although elimination/cyclization photoproduct ratios from the neat crystals are > 60 in optimal cases, the ratios of cyclobutanol diastereomers (cyclization products) remain near those observed from melt irradiations. From comparisons of the photoproduct selectivities in the neat solids and in their solid solutions, where the solvent molecules are similar in size and shape to the 2-alkanones, it is concluded that the crystalline lattices of some foreign hosts offer environments to the pre-product biradical intermediates, which are at least as restrictive as the environments of the solid 2-alkanones.

scholarly journals Combined Use of Structure Analysis, Studies of Molecular Association in Solution, and Molecular Modelling to Understand the Different Propensities of Dihydroxybenzoic Acids to Form Solid Phases

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Aija Trimdale ◽  
Anatoly Mishnev ◽  
Agris Bērziņš
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Molecular Association ◽  
Hydroxyl Groups ◽  
Solid Phases ◽  
Solvent Molecules ◽  
Dynamics Simulations

The arrangement of hydroxyl groups in the benzene ring has a significant effect on the propensity of dihydroxybenzoic acids (diOHBAs) to form different solid phases when crystallized from solution. All six diOHBAs were categorized into distinctive groups according to the solid phases obtained when crystallized from selected solvents. A combined study using crystal structure and molecule electrostatic potential surface analysis, as well as an exploration of molecular association in solution using spectroscopic methods and molecular dynamics simulations were used to determine the possible mechanism of how the location of the phenolic hydroxyl groups affect the diversity of solid phases formed by the diOHBAs. The crystal structure analysis showed that classical carboxylic acid homodimers and ring-like hydrogen bond motifs consisting of six diOHBA molecules are prominently present in almost all analyzed crystal structures. Both experimental spectroscopic investigations and molecular dynamics simulations indicated that the extent of intramolecular bonding between carboxyl and hydroxyl groups in solution has the most significant impact on the solid phases formed by the diOHBAs. Additionally, the extent of hydrogen bonding with solvent molecules and the mean lifetime of solute–solvent associates formed by diOHBAs and 2-propanol were also investigated.

scholarly journals Influence of the nature, size and shape of the solvent molecules on their diffusion in the polymer

2015 ◽  
Vol 2 (6(74)) ◽  
pp. 4
Author(s):  
Инесса Анатольевна Буртная ◽  
Отар Отарович Гачечиладзе
Keyword(s):  
Size And Shape ◽  
Solvent Molecules

Crystallographic studies of olivine-related sarcopside-type solid solutions

1984 ◽  
Vol 166 (3-4) ◽  
Author(s):  
Anders G. Nord
Keyword(s):  
Solid Solutions ◽  
Cation Distribution ◽  
Oxygen Octahedra ◽  
Size And Shape

AbstractSolid solutions ofThe cation distribution results are compared with corresponding results for olivines, orthopyroxenes, and some other oxosalt structures with metal-oxygen octahedra similar in size and shape to those in olivine. It is concluded that the Ni

THE RECIPROCAL SALT-PAIR SYSTEM: SODIUM CHLORIDE – AMMONIUM SULPHITE – SODIUM SULPHITE – AMMONIUM CHLORIDE – WATER AT 20 °C. AND 60 °C.: PART II: THE QUATERNARY SYSTEM

1955 ◽  
Vol 33 (5) ◽  
pp. 787-796 ◽  
Author(s):  
J. A. Labash ◽  
G. R. Lusby
Keyword(s):  
Sodium Chloride ◽  
Ammonium Chloride ◽  
Solid Solutions ◽  
Quaternary System ◽  
Sodium Sulphate ◽  
Sodium Sulphite ◽  
Chloride Water ◽  
Solid Phases ◽  
System Sodium

In the above quaternary system at 60 °C., besides those representing the four salts at the corners of the Janecke diagram two other saturation areas were found. At 20 °C. there are three, and possibly more than three additional areas. In the course of the present work it was not possible to establish the nature of the solid phases in these additional areas of the quaternary system. However, the data of Lewis and Rivett suggest that at least some of these unknown areas may indicate the presence of different solid solutions of sodium sulphate in sodium sulphite. This quaternary system appears to be a rather complex one and much further work remains to be done in order to complete the knowledge of it at 60 °C. and 20 °C., particularly at the latter temperature.

Characterization of Lanthanoid Phases Formed Upon Glass Dissolution in Salt Solutions

1991 ◽  
Vol 257 ◽  
Author(s):  
Anette Rother ◽  
Werner Lutze ◽  
Peter Schubert-Bischoff
Keyword(s):  
Nuclear Waste ◽  
Solid Solutions ◽  
Type Material ◽  
Salt Solutions ◽  
Detailed Characterization ◽  
Glass Dissolution ◽  
Nuclear Waste Glass ◽  
Solid Phases ◽  
Additional Barrier

ABSTRACTThis communication gives a detailed characterization of some molybdate solid solutions and cerianite-type material which formed on the French borosilicate nuclear waste glass R7T7 upon corrosion in various saturated salt solutions at 110°C, 150 °C and 190 °C. The glass contained lanthanoid elements, such as neodymium, lanthanum, praseodymium, cerium and yttrium, but did not contain actinoid elements, except uranium and thorium. Various solid solutions containing lanthanoids (Ln) were found on the glass surface after corrosion, including powellite solid solutions and cerianite-type material. The secondary solid phases are characterized based on quantitative microchemical and structural analyses. These phases are expected to incorporate actinoids such as americium and curium in acid magnesiumcontaining salt solutions. The phases then constitute an additional barrier against migration of these radionuclides, which would otherwise be in the aqueous phase.

scholarly journals Phase Equilibria and Crystal Growth for LiREF4 Scheelite Laser Crystals

2008 ◽  
Vol 1111 ◽  
Author(s):  
Detlef Klimm ◽  
Ivanildo A. Dos Santos ◽  
Izilda M. Ranieri ◽  
Sonia L. Baldochi
Keyword(s):  
Rare Earth ◽  
Crystal Growth ◽  
Phase Equilibria ◽  
Solid Solutions ◽  
Melting Behavior ◽  
Rare Earth Fluoride ◽  
Peritectic Melting ◽  
Earth Fluoride ◽  
Laser Crystals ◽  
Solid Phases

AbstractThe scheelite type laser crystals LiREF4 melt congruently only for RE being one of the elements Er, Tm, Yb, Lu, or possibly Y, respectively. For RE = Eu, Gd, Tb, Dy, or Ho the corresponding scheelites undergo a peritectic melting under the formation of the corresponding rare earth fluoride. The melting behavior of LiREF4 mixed crystals with two or more RE is not yet known well. If RE is a mixture of Gd and Lu, Gd rich solid solutions melt peritectically under formation of (Gd,Lu)F3 and Lu rich solid solutions melt directly without formation of other solid phases.

ChemInform Abstract: Solid Solutions RE16Rh11-xZx(RE: La, Ce, Pr, Nd, Sm; Z: Ga, Zn, Cd, In, Sn, Sb, Pb, Bi) - Centrosymmetric n = 2 Variants of Parthe′s Homologous Series A5n+6B3n+5.

ChemInform ◽  
2012 ◽  
Vol 43 (42) ◽  
pp. no-no
Author(s):  
Frank Tappe ◽  
Falko M. Schappacher ◽  
Thorsten Langer ◽  
Inga Schellenberg ◽  
Rainer Poettgen
Keyword(s):  
Solid Solutions ◽  
Homologous Series

Thermodynamic Modelling of Iron Solubility in Sulphide Mineral Leaching

2009 ◽  
Vol 71-73 ◽  
pp. 441-444 ◽  
Author(s):  
Pauliina Nurmi ◽  
Lasse Ahonen ◽  
Olli H. Tuovinen
Keyword(s):  
Experimental Data ◽  
Solid Solutions ◽  
Sulphide Mineral ◽  
Data Set ◽  
Iron Solubility ◽  
Hydronium Jarosite ◽  
Effects Of Ph ◽  
Solid Phases ◽  
Increasing Temperature ◽  
Mineral Leaching

In this study the effects of pH and temperature on iron solubility were predicted using the geochemical modelling code PHREEQC and the thermodynamic database WATEQ4F. The modelling results demonstrated that the solubility of secondary solid phases formed under acid bioleaching conditions decreases with increasing temperature and also with increasing pH. Modelling calculations showed that bioleaching solutions are typically supersaturated with respect to K-, Na-, NH4-, and H3O-jarosites and the precipitates are typically solid solutions containing their mixtures. Jarosite solubility modelling results were also compared with a data set from jarosite synthesis experiments. Model-derived temperature dependence of hydronium-jarosite correlated very well with the actual experimental data.

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